title: A quality comparison of protein crystals grown under containerless conditions generated by diamagnetic levitation, silicone oil and agarose gel.
abstract: High-quality crystals are key to obtaining accurate three-dimensional structures of proteins using X-ray diffraction techniques. However, obtaining such protein crystals is often a challenge. Several containerless crystallization techniques have been reported to have the ability to improve crystal quality, but it is unknown which is the most favourable way to grow high-quality protein crystals. In this paper, a quality comparison of protein crystals which were grown under three containerless conditions provided by diamagnetic levitation, silicone oil and agarose gel was conducted. A control experiment on a vessel wall was also simultaneously carried out. Seven different proteins were crystallized under the four conditions, and the crystal quality was assessed in terms of the resolution limit, the mosaicity and the Rmerge. It was found that the crystals grown under the three containerless conditions demonstrated better morphology than those of the control. X-ray diffraction data indicated that the quality of the crystals grown under the three containerless conditions was better than that of the control. Of the three containerless crystallization techniques, the diamagnetic levitation technique exhibited the best performance in enhancing crystal quality. This paper is to our knowledge the first report of improvement of crystal quality using a diamagnetic levitation technique. Crystals obtained from agarose gel demonstrated the second best improvement in crystal quality. The study indicated that the diamagnetic levitation technique is indeed a favourable method for growing high-quality protein crystals, and its utilization is thus potentially useful in practical efforts to obtain well diffracting protein crystals.
authors.affiliation: School of Life Sciences, Northwestern Polytechnical University, 127 Youyi Road, Xi'an City, Shaanxi 710072, People's Republic of China.
authors.forename: Hui-Ling
authors.initials: HL
authors.lastname: Cao
authors.forename: Li-Hua
authors.initials: LH
authors.lastname: Sun
authors.forename: Jian
authors.initials: J
authors.lastname: Li
authors.forename: Lin
authors.initials: L
authors.lastname: Tang
authors.forename: Hui-Meng
authors.initials: HM
authors.lastname: Lu
authors.forename: Yun-Zhu
authors.initials: YZ
authors.lastname: Guo
authors.forename: Jin
authors.initials: J
authors.lastname: He
authors.forename: Yong-Ming
authors.initials: YM
authors.lastname: Liu
authors.forename: Xu-Zhuo
authors.initials: XZ
authors.lastname: Xie
authors.forename: He-Fang
authors.initials: HF
authors.lastname: Shen
authors.forename: Chen-Yan
authors.initials: CY
authors.lastname: Zhang
authors.forename: Wei-Hong
authors.initials: WH
authors.lastname: Guo
authors.forename: Lin-Jun
authors.initials: LJ
authors.lastname: Huang
authors.forename: Peng
authors.initials: P
authors.lastname: Shang
authors.forename: Jian-Hua
authors.initials: JH
authors.lastname: He
authors.forename: Da-Chuan
authors.initials: DC
authors.lastname: Yin
mesh_terms: D000818:Animals; D002645:Chickens; D003460:Crystallization / Q000379:methods / Q000592:standards; D018360:Crystallography, X-Ray / Q000379:methods / Q000592:standards; D029968:Escherichia coli Proteins / Q000737:chemistry; D006112:Gravitation; D009682:Magnetic Resonance Spectroscopy; D056951:Photoelectron Spectroscopy; D011506:Proteins / Q000737:chemistry* / Q000592:standards; D011786:Quality Control; D012685:Sepharose / Q000592:standards*; D012827:Silicone Oils / Q000592:standards*; D029778:Trichosanthes; D014961:X-Ray Diffraction / Q000379:methods / Q000592:standards
chemical_list: D029968:Escherichia coli Proteins; D011506:Proteins; D012827:Silicone Oils; D012685:Sepharose
keywords: agarose gel; containerless crystallization; diamagnetic levitation; diffraction quality; morphology; protein crystallization; silicone oil